U.S. patent number 8,454,621 [Application Number 11/523,408] was granted by the patent office on 2013-06-04 for instruments and methods for spinal implant revision.
This patent grant is currently assigned to Warsaw Orthopedic, Inc.. The grantee listed for this patent is Steven D. DeRidder, Brian Robert Thoren. Invention is credited to Steven D. DeRidder, Brian Robert Thoren.
United States Patent |
8,454,621 |
DeRidder , et al. |
June 4, 2013 |
Instruments and methods for spinal implant revision
Abstract
Instruments and methods are provided for re-positioning and
extracting spinal implants in a space between vertebrae. The
instruments can include rotator instruments, hook instruments, and
extractor instruments engageable to the implant. A method for
manipulating a spinal implant in a space between vertebrae includes
positioning a spinal implant in the space between vertebrae;
engaging the spinal implant with a hook member at a distal end of a
hook instrument; pulling the spinal implant toward an opening into
the space between the vertebrae; grasping the spinal implant with
an engaging assembly of an extractor instrument; and removing the
spinal implant from the space with the extractor instrument.
Inventors: |
DeRidder; Steven D. (Bartlett,
TN), Thoren; Brian Robert (Memphis, TN) |
Applicant: |
Name |
City |
State |
Country |
Type |
DeRidder; Steven D.
Thoren; Brian Robert |
Bartlett
Memphis |
TN
TN |
US
US |
|
|
Assignee: |
Warsaw Orthopedic, Inc.
(Warsaw, IN)
|
Family
ID: |
39125232 |
Appl.
No.: |
11/523,408 |
Filed: |
September 19, 2006 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20080097454 A1 |
Apr 24, 2008 |
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Current U.S.
Class: |
606/99;
623/17.16 |
Current CPC
Class: |
A61F
2/4611 (20130101); A61F 2002/4627 (20130101); A61F
2002/30538 (20130101); A61F 2002/30784 (20130101); A61F
2002/30133 (20130101); A61F 2250/0006 (20130101); A61F
2002/4619 (20130101); A61F 2230/0015 (20130101); A61F
2002/4628 (20130101); A61F 2/442 (20130101) |
Current International
Class: |
A61B
17/88 (20060101); A61B 17/92 (20060101); A61B
17/58 (20060101); A61F 2/44 (20060101) |
Field of
Search: |
;606/246,279,86R,99,90,100 ;623/17.11,17.16 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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202004014120 |
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Dec 2004 |
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DE |
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WO02/091909 |
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Nov 2002 |
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WO |
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Primary Examiner: Schaper; Michael T
Claims
What is claimed is:
1. A method for manipulating a spinal implant in a space between
vertebrae, comprising: accessing a spinal implant positioned in the
space between vertebrae through an opening into the space formed
along a postero-lateral approach to the space, wherein the
positioned spinal implant includes a wall with a first portion at a
proximal side of the space closest to the opening and the wall of
the positioned spinal implant includes a second portion at a distal
side of the space opposite the proximal side; positioning a rotator
through the opening to contact the second portion of the wall of
the positioned spinal implant at the distal side of the space with
a distal end of the rotator; moving the positioned spinal implant
in the space to a desired orientation by pushing the second portion
of the wall of the spinal implant at the distal side of the space
with the distal end of the rotator; engaging the spinal implant
with a hook member at a distal end of a hook instrument; pulling
the spinal implant toward the opening into the space between the
vertebrae; grasping the spinal implant with an engaging assembly of
an extractor instrument; and removing the spinal implant from the
space with the extractor instrument.
2. The method of claim 1, further comprising: pivoting the spinal
implant in the space to the desired orientation in the space with
the rotator.
3. The method of claim 1, wherein pulling the spinal implant
includes pivoting the spinal implant with the hook instrument.
4. The method of claim 1, wherein engaging the spinal implant with
the hook member includes positioning the hook member in a
receptacle in a wall of the spinal implant.
5. The method of claim 4, wherein engaging the spinal implant with
the hook member includes selecting between a first hook instrument
with a hook member formed by a linear arm and a hooked end at a
distal end of said linear arm and a second hook instrument with a
hook member formed by an angled arm and a hooked end at a distal
end of said angled arm.
6. The method of claim 1, wherein grasping the spinal implant with
the engaging assembly includes positioning a support member of the
engaging assembly in a receptacle of the spinal implant and
linearly advancing a clamping member into a second receptacle of
the spinal implant to clampingly engage the spinal implant between
the support member and the clamping member.
7. The method of claim 1, wherein grasping the spinal implant with
the engaging assembly includes positioning a support member of the
engaging assembly in a receptacle of the spinal implant and
pivotally advancing a clamping member toward the support member and
into a second receptacle of the spinal implant to clampingly engage
the spinal implant between the support member and the clamping
member.
8. The method of claim 1, wherein the rotator includes an elongated
shaft extending along a longitudinal axis, a handle at a proximal
end of the shaft, and a distal end member at a distal end of the
shaft, the distal end member including a distal end wall extending
thereacross.
9. The method of claim 8, wherein the elongated shaft includes a
proximal shaft portion offset from the longitudinal axis.
10. The method of claim 8, wherein the distal end member includes
first and second feet that extend in opposite directions from one
another away from the longitudinal axis.
11. The method of claim 10, wherein the first foot includes a first
width extending outwardly from the longitudinal axis and the second
foot includes a second width extending outwardly from the
longitudinal axis, the first width being greater than the second
width.
12. The method of claim 11, wherein the first and second feet
diverge away from one another in a distal direction along the
longitudinal axis.
13. The method of claim 12, wherein the distal end wall is
concavely curved along an arc defined by a radius having a center
offset from the longitudinal axis.
Description
BACKGROUND
Normal intervertebral discs between endplates of adjacent vertebrae
distribute forces between the vertebrae and cushion vertebral
bodies. The spinal discs may be displaced or damaged due to trauma,
disease or aging. A herniated or ruptured annulus fibrosis may
result in nerve damage, pain, numbness, muscle weakness, and even
paralysis. Furthermore, as a result of the normal aging processes,
discs dehydrate and harden, thereby reducing the disc space height
and producing instability of the spine and decreased mobility. Most
surgical corrections of a disc space include a discectomy, which
can be followed by restoration of normal disc space height and bony
fusion of the adjacent vertebrae to maintain the disc space
height.
Other procedures can involve removal of one or more vertebral
bodies as a result of trauma, disease or other condition. An
implant can be positioned between intact vertebrae to provide
support until fusion of the affected spinal column segment is
attained.
Access to a damaged disc space or to a corpectomy location may be
accomplished from several approaches to the spine. One approach is
to gain access to the anterior portion of the spine through a
patient's abdomen. A posterior or lateral approach may also be
utilized. Postero-lateral, antero-lateral and oblique approaches to
the spinal column have also been employed to insert implants.
Whatever the approach, there may be a need to re-position and/or
extract implants after positioning in the spinal disc space or
corpectomy location. There remains a need for improved instruments
and techniques for use in any approach that facilitate revision of
spinal implants in a space between vertebrae.
SUMMARY
There are provided instruments and methods useful for implant
re-positioning and extraction from any approach to the spine. Such
implants can be employed in disc replacement and/or vertebral body
replacement type procedures. The instruments can be provided in a
kit to provide the surgeon a variety of instrument options during
the procedure.
In one aspect, an assembly for spinal implant revision includes a
rotator instrument with an elongate shaft extending along a
longitudinal axis, a proximal handle extending from a proximal end
of the shaft, and a distal end member at a distal end of the shaft.
The distal end member includes a first foot including a first width
extending from the longitudinal axis and a second foot including a
second width less than the first width extending from the
longitudinal axis in a direction opposite the first foot. The
distal end member includes a concave distal end wall extending
along the first and second feet. The assembly also includes an
implant sized and shaped for positioning in a space between
vertebrae that includes a wall and at least a portion of the wall
has a convex shape that corresponds to a shape of the concave
distal end wall.
In another aspect, an assembly for spinal implant revision includes
an elongate shaft extending along a longitudinal axis, a proximal
handle extending from a proximal end of the shaft, and a distal
hook member extending distally from the shaft. The hook member
includes an elongate arm extending along the longitudinal axis and
a hooked end at a distal end of the arm. The assembly also includes
an implant sized and shaped for positioning in a space between
vertebrae. The implant includes a receptacle and the hooked end is
positioned in the receptacle in engagement with the implant.
In a further aspect, an instrument for engaging a spinal implant
includes a shaft assembly, an actuator assembly at a proximal end
of the shaft assembly, and an engaging assembly at a distal end of
the shaft assembly. The engaging assembly includes a support member
fixedly coupled with the shaft assembly and extending distally
therefrom and a clamping member coupled with at least one of the
shaft assembly and the support member. The actuator assembly is
operably linked to the clamping member with the shaft assembly. The
clamping member is movable toward the support member with actuation
of the actuator assembly to a clamping position for clampingly
engaging the implant between the support member and the clamping
member. The support member includes an elongated body with a linear
proximal section and a distal section angled relative to the
proximal section. The distal section includes a flange at a distal
end thereof forming a proximally oriented lip extending toward the
clamping member and positionable in engagement with the
implant.
In another aspect, a kit for repositioning and extracting spinal
implants includes a spinal implant, a rotator instrument, at least
one hook instrument and at least one extractor instrument. The
rotator instrument includes a shaft extending along a longitudinal
axis, a proximal handle and a distal end member. The distal end
member includes a distal end wall with a shape to conform to a
portion of a wall of the implant.
The hook instrument includes a shaft extending along a longitudinal
axis between a proximal handle and a distal hook member configured
to engage the implant in a receptacle of the implant. The extractor
instrument includes a shaft assembly operably linking a proximal
actuator assembly and a distal engaging assembly. The distal
engaging assembly is operable with the actuator assembly to
clampingly engage the implant.
According to one aspect, a method for manipulating a spinal implant
in a space between vertebrae comprises: positioning a spinal
implant in the space between vertebrae; engaging the spinal implant
with a hook member at a distal end of a hook instrument; pulling
the spinal implant toward an opening into the space between the
vertebrae; grasping the spinal implant with an engaging assembly of
an extractor instrument; and removing the spinal implant from the
space with the extractor instrument.
These and other aspects will also be apparent from the following
description and the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of vertebral space with an implant and a
distal portion of a rotator instrument.
FIG. 2 is a plan view of a vertebral space with an implant and a
distal portion of a hook instrument.
FIG. 3 is a plan view of a vertebral space with an implant and a
distal portion of another embodiment hook instrument.
FIG. 4 is a plan view of an implant with a distal portion of an
extractor instrument engaged thereto.
FIG. 5 is a plan view of an implant with another embodiment distal
portion of an extractor instrument engaged thereto.
FIG. 6 is a plan view of a rotator instrument.
FIG. 7 is a plan view of a distal end portion of the rotator
instrument of FIG. 6.
FIG. 8 is a perspective view of an adjustment instrument.
FIG. 9 is a perspective view of a hook instrument.
FIG. 10 is an elevation view of a distal hook member of the hook
instrument of FIG. 9.
FIG. 11 is an end view of the hook member of FIG. 10.
FIG. 12 is a side view of another embodiment hook member.
FIG. 13 is an elevation view of an extractor instrument.
FIG. 14 is an exploded perspective view of the extractor instrument
of FIG. 13.
FIG. 15 is a section view of the mounting assembly of the extractor
instrument.
FIG. 16 is a section view of the mounting assembly.
FIG. 17 is a section view of the mounting assembly.
FIG. 18 is a section view along line 18-18 of FIG. 17.
FIG. 19 is an elevation view of a trigger of the extractor
instrument of FIG. 13.
FIG. 20 is a top plan view of a rail member of the extractor
instrument of FIG. 13.
FIG. 21 is an elevation view of the rail member of FIG. 20.
FIG. 22 is a section view along line 22-22 of FIG. 20.
FIG. 23 is a section view along line 23-23 of FIG. 20.
FIG. 24 is a section view along line 24-24 of FIG. 21.
FIG. 25 is a section view along line 25-25 of FIG. 21.
FIG. 26 is a top plan view of a support member of the engaging
assembly of the extractor instrument of FIG. 13.
FIG. 27 is an elevation view of the support member of FIG. 26.
FIG. 28 is an elevation view of a clamping member of the engaging
assembly of the extractor instrument of FIG. 13.
FIG. 29 is an elevation view of another embodiment extractor
instrument.
FIG. 30 is an exploded perspective view of the extractor instrument
of FIG. 29.
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS
For the purposes of promoting an understanding of the principles of
the present invention, reference will now be made to the
embodiments illustrated in the drawings, and specific language will
be used to describe the same. It will nevertheless be understood
that no limitation of the scope of the invention is intended
thereby. Any alterations and further modification in the described
processes, systems, or devices, and any further applications of the
principles of the invention as described herein are contemplated as
would normally occur to one skilled in the art to which the
invention relates.
Instruments and techniques provide and facilitate implant
re-positioning in and extraction from a space between vertebral
bodies. The instruments can be provided in a kit to provide the
surgeon with various options and capabilities during the procedure.
The instruments and techniques can be employed in any approach to
the space and with implants of any size and configuration. The
implants can further be positioned in a spinal disc space between
vertebrae or in a space provided by removal of all or a portion of
one or more vertebral bodies in a corpectomy procedure. As used
herein, the space between vertebrae is intended to encompass the
space between adjacent vertebral bodies in intradiscal procedures
and the space between vertebrae provided by removal of all or a
portion of one or more vertebral bodies.
The instruments can include rotator instruments that can contact a
wall of the implant to allow application of rotational and
translational forces to re-position or re-orient the implant in the
space between vertebrae. Hook instruments are also provided that
allow a receptacle in the implant to be engaged with a hook member
while the implant is in the space. The hook instrument can then be
manipulated to remove or re-position the implant. Also provided are
extractors with a proximal actuating structure and a distal implant
engaging assembly operable by the proximal actuating structure to
positively engage the implant. The implant engaging assembly can be
pivotally or linearly movable to engage the implant in the space.
Slap hammers, mallets, tuning instruments and other manipulators
can be employed to facilitate application of re-positioning and
removal forces adjacent the proximal ends of the instruments.
Referring to FIG. 1, there is shown a space S adjacent vertebral
body V. Implant 50 is positioned in space S. In the illustrated
embodiment, a postero-lateral approach A is shown, it being
understood that other portal locations and approaches are
contemplated. Implant 50 can be an intradiscal implant or a
corpectomy device. Implant 50 can further include a banana or
concavo-convex shape in plan view with the convex wall anteriorly
oriented as shown, or any other suitable shape, including
rectangular shapes, oval shapes, circular shapes, D-shapes, square
shapes or irregular shapes. Implant 50 can be made from any
suitable bio-compatible material, including bone material, metals
and metal alloys, polymers, ceramics, carbon fiber, and
combinations thereof.
A distal portion of a rotator instrument 100 is shown in FIG. 1
with a distal end member 102 contacting wall 52 of implant 50
adjacent a distal side D of the space S. As used herein, the
proximal side P of space S is the side closest to the approach
through which the instrument is positioned, and distal side D of
the space S is opposite the proximal side P. Distal end member 102
includes a concave end wall 104 positionable in contact with
implant 50 to allow application of re-positioning forces along a
portion of the wall 52 of implant 50. An elongated shaft 106
extends proximally from end member 102 to allow remote manipulation
of the implant 50, including contact with the side of implant 50
that is located or to be located opposite the approach A. For
example, pushing forces directed along the longitudinal axis of the
instrument as indicated by arrow 70 can be applied with rotator
instrument 100 to rotate implant 50 into a desired orientation.
Simultaneously or alternately, pivoting or rotational forces can be
applied as indicated by bi-directional arrow 72. The implant 50 can
thus be pivoted and translated in the space to a desired position
from an initial insertion position, or moved from an implanted
position to facilitate access and removal of implant 50 by one or
more other instruments.
In FIG. 2 there is shown a hook instrument 140 and implant 50 in
sectional view.
Implant 50 includes a receptacle 54 in wall 52. Receptacle 54 can
extend partially or completely through wall 52. Hook instrument 140
includes a shaft 142 and a distal hook member 144 at a distal end
of shaft 142. Hook member 144 includes an arm 148 extending to a
hooked end 146 that can be engaged in receptacle 54 to engage the
implant and deliver forces to rotate or pivot it in space S, as
indicated by bi-directional arrows 72, and alternately or
simultaneously deliver forces that move implant 50 proximally in
space S toward proximal side P as indicated by arrow 74.
In FIG. 2, hook member 144 includes arm 148 with a linear
configuration extending to hooked end 146. In FIG. 3, another
embodiment hook instrument 160 is shown with a hook member 164
including an angled configuration extending to a hooked end 166.
Hook member 164 includes angled arm 168 including a first proximal
section 170 extending from shaft 162 and a second distal section
172 angled relative to and extending distally from first proximal
section 170 to hooked end 166. The angled arm 168 allows shaft 162
to be positioned at angles relative to implant 50 that differ than
those provided by linear hook member 144.
Referring to FIG. 4, there is shown an extractor instrument 200
engaged to implant 50'. Implant 50' can be similar to implant 50
discussed above, and is shown in sectional view. Implant 50'
includes wall 52' including a first receptacle 54' along one side
thereof and a second receptacle 58' on or along a second side
thereof. Receptacles 54', 58' can extend through or partially into
wall 52', and can include any size or shape.
Extractor instrument 200 includes a shaft assembly 202 with a
mounting assembly 204 and a rail assembly 240 movably mounted to
mounting assembly 204. An engaging assembly 206 is provided at the
distal end of shaft assembly 202 that is movable to clampingly
engage implant 50'. Mounting assembly 204 includes a mounting
member 208 and engaging assembly 206 includes a distal support
member 210 extending distally from mounting member 208. Rail
assembly 240 includes an elongated rail member 242 movable along
mounting member 208 and engaging assembly 206 includes a distal
clamping member 244 movably coupled to rail member 242. A linking
portion 245 pivotally links clamping member 244 with one of support
member 210 and mounting member 208. Longitudinal displacement of
rail member 242 with a proximal actuating assembly (discussed
further below) as indicated by bi-directional arrow 76 pivots
clamping member 244 into and out of engagement with implant 50' as
indicated by bi-directional arrow 78. Clamping member 244 works in
conjunction with a flanged end 212 of support member 210 to
clampingly engage implant 50' therebetween with flanged end 212 in
receptacle 58' and clamping member 244 in receptacle 54'. With the
implant 50' so engaged, implant 50' can be pivoted, rotated,
translated and/or extracted from space S with extractor instrument
200.
In FIG. 5, there is shown another embodiment extractor instrument
400 that includes a shaft assembly 402 with a mounting assembly 404
and a rail assembly 440 movably mounted to mounting assembly 404.
An engaging assembly 406 is provided at the distal end of shaft
assembly 402 that is longitudinally movable to clampingly engage
implant 50'. Mounting assembly 404 includes a mounting member 408
and engaging assembly 406 includes a distal support member 410
extending distally from mounting member 408. Rail assembly 440
includes an elongated rail member 442 movable along mounting member
408 and engaging assembly 406 includes a distal clamping member 444
that moves longitudinally with rail member 442 as indicated by
bi-direction arrow 80 with a proximal actuating assembly (discussed
further below.) Clamping member 444 works in conjunction with a
flanged end 412 of support member 410 to clampingly engage implant
50' therebetween with flanged end 412 in receptacle 58' and
clamping member 444 axially received in a receptacle 56' in wall
52'. With the implant 50' so engaged, implant 50' can be pivoted,
rotated, translated and/or extracted from space S with extractor
instrument 400.
Referring now to FIGS. 6 and 7, further details of rotator
instrument 100 will be discussed. Rotator instrument 100 includes
elongated shaft 106 including a proximal handle 108 and distal end
member 102 at a distal end of shaft 106 opposite handle 108. Distal
end member 102 includes distally oriented end wall 104. Shaft 106
can include a distal shaft portion 112 extending along longitudinal
axis 110 and a proximal shaft portion 114 offset from axis 110 with
a pair of bends 116, 117 and an oblique shaft portion 118 extending
obliquely to distal and proximal shaft portions 112, 114. The
offset can facilitate viewing of distal end member 102 and the
implant in contact therewith by positioning handle 108 out of the
field of view. Handle 108 can be removably engaged to shaft 106 or
formed integrally therewith. Embodiments with a non-offset shaft
configuration are also contemplated.
In FIG. 7, distal end member 102 is shown and includes opposite
feet 120, 122 extending in opposite directions from longitudinal
axis 110. In the illustrated embodiment, first foot 120 extends
outwardly a first width W1 and second foot 122 extends outwardly a
second width W2. In one embodiment, width W1 is about 50% greater
than width W2, although other arrangements are contemplated ranging
from a difference of about 0% to a difference of about 100% or
more. In addition, end member 102 includes feet 120, 122 that
diverge distally from one another along an angle A1. Foot 120
extends along an angle A2 measured from longitudinal axis 110 that
is less than the angle of foot 122 from longitudinal axis 110. In
one embodiment, angle A1 is 90 degrees and angle A2 is 35 degrees.
Other angular arrangements are also contemplated. The differing
widths and angular relationships can facilitate pivoting movement
of the implant by allowing the greater width foot 120 to pivot the
implant toward the direction of shorter foot 122 without
obstruction by the shorter foot 122.
End wall 104 can be concave and extend along an arc defined by a
radius R. Radius R can be offset from axis 110 by a distance D1,
although alignment of the center of radius R along axis 110 is also
contemplated. Arc A can be provided with a shape to generally
conform to a curvature of a wall portion of the implant to be
contacted with end wall 104 to facilitate control of the implant
and distribution of re-positioning forces over a larger surface
area of the implant. Other embodiments contemplate other
configurations for end wall 104, including a concave shape formed
by linear and/or angular wall portions and implants with wall
portions generally conforming in shape thereto.
FIG. 8 shows a tuning instrument 300 with a proximal handle 302, an
intermediate shaft 304 and a distal instrument engaging structure
306. Engaging structure 306 includes a forked shape with a
receptacle 308 between arms 310, 312 that can receive a shaft of an
instrument. As discussed further below, arms 310, 312 can contact
an adjustment member of the instrument to facilitate application of
re-positioning and extraction forces to the instrument by
manipulating tuning instrument 300, and thus tune or adjust the
position of the implant in contact with the instrument.
In FIG. 9 there is shown hook instrument 140. Hook instrument 140
includes shaft 142 and hook member 144 at a distal end of shaft
142. Shaft 142 extends along longitudinal axis 143. Hook instrument
140 further includes a proximal handle 150 at a proximal end of
shaft 142 and an adjustment member 152 extending outwardly from
shaft 142 distally of handle 150. Adjustment member 152 can be
contacted with an adjustment member, such as tuning instrument 300,
at the proximal or distal sides thereof to facilitate application
of adjustment forces to hook instrument 140 and thus to an implant
engaged thereby.
Hook member 144 is shown in further detail in FIGS. 10 and 11. Hook
member 144 includes a linear arm 148 extending and centered along
longitudinal axis 143. Hook member 144 includes a proximal end
member 154 that is engageable to shaft 142 by a press fit and epoxy
or other suitable engagement structure or means, including
fasteners, welding and the like. Hooked end 146 includes a first
hook portion 146a transversely oriented to longitudinal axis 143
and linear arm 148, and a second hook portion 146b that extends
from first hook portion 146a proximally and generally parallel to
longitudinal axis 143. Hooked portion 146b is spaced from arm 148
to provide a space to engage the implant in hooked end 146. In one
embodiment, first hook portion 146a includes a length L1 that is
about 50% greater than a length L2 of second hook portion 146b. The
lengths L1 and L2 can facilitate positioning of hooked end 146 in a
receptacle and in engagement to the implant with the implant in
space S while minimizing intrusion of hook instrument 140 into the
adjacent tissue during engagement and disengagement with the
implant. Other embodiments contemplate other relationships between
the length of hook portions 146a, 146b, including lengths that are
the same and lengths where hook portion 146b has a length greater
than hook portion 146a.
As shown in FIG. 11, hooked end 146 can include a square-shaped
cross-section to facilitate engagement with the implant in a manner
that prevents or reduces rotation of the hooked end relative to the
implant. Other embodiments contemplate other shapes for hooked end
146 and arm 148, including circular, rectangular, oval, polygonal,
and non-circular shapes.
Referring now to FIG. 12, there is shown hook member 164, it being
understood that hook instrument 160 could be provided with a shaft
and handle structure like that discussed above for hook instrument
140. Hook member 164 includes angled arm 168 including proximal
section 170 extending along longitudinal axis 163. Distal section
172 is angled relative to longitudinal axis 163 and proximal
section 170 at an angle A2. In one embodiment, angle A2 is about 45
degrees, although other angular relationships are contemplated. The
angular relationship facilitates positioning of the hook member 164
around a curved portion or bend of the implant body while
minimizing intrusion of the hook member 164 into the adjacent
tissue. Distal section 172 can have a length L3 extending to hooked
end 166. Hooked end 166 includes a first portion 166a extending
transversely to distal section 172 along a length L4 and a second
portion 166b extending proximally from an end of first portion 166a
along length L5 in a generally parallel and spaced relationship to
distal section 172. In the illustrated embodiment, length L3 is
greater than length L4 which is greater than length L5. Other
arrangements contemplate other relationships between lengths L3, L4
and L5.
In FIGS. 13 and 14, there is shown extractor instrument 200
including shaft assembly 202 with mounting assembly 204 and rail
assembly 240 mounted to mounting assembly 204. Engaging assembly
206 is provided at the distal end of shaft assembly 202 and is
movable with an actuating assembly 270 to clampingly engage an
implant.
Mounting assembly 204 includes mounting member 208 and rail
assembly 240 includes an elongated rail member 242 movable along
mounting member 208. Engaging assembly 206 includes distal support
member 210 fixedly engaged to and extending distally from mounting
member 208 and distal clamping member 244 movably coupled to rail
member 242 with a first pin 298. Clamping member 244 includes a
proximal linking portion 245 pivotally coupled with support member
210 with second pin 299. Longitudinal displacement of rail member
242 with proximal actuating assembly 270 translates pin 298 along
clamping member 244 and pivots clamping member 244 about pin 299
into and out of engagement with the implant. Clamping member 244
works in conjunction with a flanged end 212 of support member 210
to clampingly engage the implant therebetween for re-positioning in
and/or extraction of the implant from the space S with extractor
instrument 200.
Mounting member 208 includes an elongated body extending between a
distal end 214 and a proximal handle structure 216. An adjustment
member 220 is provided extending proximally from handle structure
216 for engagement with an adjustment instrument, such as a slap
hammer. An intermediate housing portion 218 is provided between
handle structure 216 and mounting member 208. Housing portion 218
is configured for engagement with a trigger 272 of actuating
assembly 270.
As shown in FIG. 19, trigger 272 includes a hand-hole portion 274
and an upper arm 276. Upper arm 276 includes a groove 278 and a
central hole 280 extending therethrough. A locking hole 282 is
provided between hand-hole portion 274 and central hole 280.
Locking hole includes a through slot 282a and a recessed portion
282b extending about and off-center relative to slot 282a along one
side of upper arm 276. Hand-hole portion 274 is sized to receive
one or more fingers of the user's hand. Other arrangements for
trigger 272 are also contemplated, such as where no hole is
provided and one or more fingers of the user's hand extend around
the trigger.
Referring now to FIG. 15, housing portion 218 includes a central
slot 222 extending therethrough to receive arm 276 of trigger 272.
Housing portion 218 further includes a first bore 224 to receive a
mounting pin 290 (FIG. 14) through central hole 280 to pivotally
couple trigger 272 to housing portion 218. In the illustrated
embodiment, one side of bore 224 is threaded to threadingly engage
mounting pin 290 while hole 280 is sized to allow rotation of
trigger 272 about mounting pin 290. Housing portion 218 also
includes a second bore 226 configured to receive a spring loaded
locking pin 292, spring 294, and locking button 296. Locking button
292 includes a first portion 292a that is positioned in slot 282a
in a manner that allows trigger 272 to be pivoted about mounting
pin 290 to a position that engages the implant with engaging
assembly 206. In this engaged position, a second, enlarged portion
292b of locking pin 292 is aligned with recess 282b, and spring 294
biases the enlarged portion 292b into recess 282b to lock trigger
272 and thus engaging assembly 206 to the implant. When it is
desired to release the implant, button 296 can be pressed to force
the enlarged portion 292b out of recess 282b and orient first
portion 292a in slot 282a so that the trigger can move back along
first portion 292a to the disengaged position.
Mounting member 208 further includes a proximal inverted T-shaped
longitudinal slot 228 as shown in FIGS. 16 and 18 extending
therealong and opening along an upper surface thereof proximally of
central slot 222 to receive a proximal rail portion of rail member
242, as discussed further below. As shown in FIGS. 17 (with support
member 210 removed) and 18, mounting member 208 includes a distal
inverted T-shaped longitudinal slot 230 extending therealong
adjacent distal end 214 to a distal rail portion of rail member
242, as discussed further below. Mounting member 208 also includes
a bottom groove 232 adjacent distal end 214 that can receive
support member 210, as discussed further below.
Referring now to FIGS. 20-21 there is shown rail member 242. Rail
member 242 includes an elongated body extending between a distal
mounting portion 246 and a proximal mounting portion 248. As shown
further in FIG. 22, distal mounting portion 246 includes a pair of
fingers 250 including holes 252 therethrough to receive mounting
pin 298 to couple clamping member 244 to distal mounting portion
246. Second mounting pin 299 pivotally couples clamping member 244
to support member 210. As shown in FIG. 24, an inverted T-shaped
rail portion 255 extends down from rail member 242 along distal
mounting portion 246. Rail portion 255 is positionable in distal
longitudinal slot 230 to secure rail member 242 along mounting
member 208 while permitting longitudinal sliding movement
therebetween. As shown in FIG. 25, proximal mounting portion 248
further includes a proximal T-shaped rail portion 262 that is
slidably received in proximal longitudinal slot 228 of mounting
member 208 while permitting longitudinal sliding movement
therebetween.
Referring further to FIGS. 23 and 25, proximal mounting portion 248
will be further discussed. Proximal mounting portion 248 includes a
body that increases in cross-sectional width and height to provide
increased strength and stability along proximal mounting portion
248. Proximal mounting portion 248 includes an intermediate
projection 256 extending therefrom that is received in a distal
portion 223 (FIG. 18) of central slot 222 of housing portion 218.
There is further provided a recessed area 258 including side holes
260 to receive a pin 261 (FIG. 13) that is positioned in groove 278
of trigger 272 (FIG. 19). Trigger 272 can pivot about pin 261 while
upper arm 276 is movable in recessed area 258. Pin 261 assists in
maintaining the desired orientation and positioning of trigger 272
relative to mounting portion 248. In addition, spring member 286 is
positioned in distal portion 223 of central slot 222 and distally
of intermediate projection 256. Spring member 286 contacts a distal
end wall 225 (FIG. 18) of distal portion 223 and extends to a
proximal end that contacts projection 256 to proximally bias rail
member 242. Spring 286 also proximally biases upper arm 276 of
trigger 272 about mounting pin 290 since trigger 272 is coupled to
rail member 242 with pin 261. Spring 286 normally biases engaging
assembly 206 to an open position. When trigger 272 is squeezed,
rail member 242 is distally displaced against the bias of spring
286 by the upper arm 276 rotating about mounting pin 90 and
displacing rail member 242 through its engagement thereto with the
pin 261 in side holes 260.
Referring now to FIGS. 26 and 27, there is shown support member
210. Support member 210 includes a proximal tongue 320 configured
for positioning in bottom groove 232 of mounting member 208 and
securable therein with a press fit, epoxy, welding, fasteners
and/or other suitable connecting arrangements. Support member 210
further includes a body portion 322 with a central slot 324 and
side holes 326 to receive mounting pin 299 (FIG. 14). Body 322
includes a linear proximal section 323 and a distal section 325
angled relative to proximal section 323 toward clamping member 244.
Support member 210 includes flange 212 at the distal end of distal
section 325 that extends toward clamping member 244. Flange 212
forms a proximally oriented lip 213 that extends toward clamping
member 244. The fixed relationship of support member 210 and angled
body 322 facilitates placement of support member 210 into the space
and around the implant without bending or pivoting of support
member 210 so flange 212 can engage a receptacle in the
implant.
In FIG. 28 there is shown clamping member 244 with proximal linking
portion 245 including a through-hole 330 to receive mounting pin
299 and pivotally couple clamping member 244 in slot 324 of support
member 210. Clamping member 244 includes an angled portion 336
extending from linking portion 245. Angled portion 336 includes an
angled slot 332 through which pin 298 extends. Slot 332 includes a
proximal end 332a and a distal end 332b that are both offset toward
support member 210 when assembled thereto. Slot 332 defines an
arcuate path angled away from support member 210 at a mid-portion
thereof between ends 332a, 332b that is configured to provide
positive seating of flange 334 with a receptacle or other structure
of the implant. Clamping member 244 further includes an extension
portion 338 that forms a concave recess 340 therealong oriented
toward support member 210 to facilitate positioning of clamping arm
244 around the implant. Flange 334 is provided at the distal end of
extension portion 338, and forms a proximally oriented lip 342
positionable in contact with the implant in conjunction with the
proximally oriented lip formed by flange 212. The lips 213, 342
axially restrain the implant to engaging assembly 206 during
re-positioning and extraction of the implant.
When assembled as shown in FIG. 13, trigger 272 is movable to
longitudinally and distally displace upper rail member 242 of rail
assembly 240 against the bias of spring 286. This movement in turn
moves pin 298 along slot 332 of clamping member 244 from proximal
end 332a toward distal end 332b. Clamping member 244 in turn pivots
about its engagement with support member 210 so that flanged end
334 moves toward flanged end 212, clamping the implant therebetween
with engaging assembly 206. The clamped engagement can be
maintained by locking pin 292 positively engaging trigger 272 in
the closed position. A slap hammer, tuning fork or other instrument
can be engaged to adjustment member 220 to facilitate application
of re-positioning and/or removal forces to move the implant in
space S. When the implant has been re-positioned or removed, the
trigger 272 can be unlocked by depressing button 296 to displace
locking pin 292 relative to the trigger 272, and spring 286 biases
rail member 242 proximally to pivot clamping member 244 away from
support member 210 and release the implant from engaging assembly
206.
Referring to FIGS. 29-30, there is shown another embodiment
extractor instrument 400 that is similar to extractor instrument
200, except that engaging assembly 406 does not include a pivoting
arrangement but rather a longitudinal sliding arrangement. Trigger
472 is pivotally coupled with mounting assembly 402 with mounting
pin 490 and linked to upper rail member 442 of rail assembly 440
with pin 443. Rail member 442 can be secured to and longitudinally
movable along mounting member 408 with a rail and slot arrangement
in a manner similar to that discussed above with respect to
extractor instrument 200, except that there is no proximal spring
bias of rail member 442, although such is not precluded. Mounting
member 408 includes a support member 410 of engaging assembly 406
extending distally therefrom. Support member 410 can be configured
like support member 210 discussed above, but does not include any
slot to receive clamping member 444.
Upper rail member 442 includes clamping member 444 in the form of a
cylinder with a rounded distal end formed by a bullet or
ball-shaped tip that can be positioned in an implant receptacle. In
use, support member 410 is positioned along one side of the implant
with the hooked end in engagement with an implant receptacle.
Trigger 472 is squeezed to distally and longitudinally displace
rail member 442 and thus clamping member 444 toward the implant.
When clamping member 444 is positioned in the implant receptacle,
the implant is clamped between support member 410 and clamping
member 444, and extraction or re-positioning of the implant can be
performed with extractor instrument 400 as discussed above with
respect to extractor instrument 200.
It is contemplated that the above-described instruments and methods
can be used in substantially open surgical procedures. It is also
contemplated that the instruments and methods may be utilized
through guide sleeves or tubes. Sleeves and tubes can provide
greater protection to adjacent tissues, reduce the size of access
incisions, provide direct visualization of the surgical site,
and/or provide enhanced control of the procedure. The instruments
and methods may further be used in combination with disc space
preparation and implant insertion through microscopic or endoscopic
instruments that provide direct visualization of the surgical
site.
The instruments discussed herein are suited for re-positioning and
extracting an implant in a space between vertebrae for revision
procedures. The rotator and hook instruments provide the surgeon
the ability to re-position an implant in the space to a desired
implantation orientation, or to re-position the implant for
engagement with one of the extractor instruments. The rotator
instruments can pivot and translate the implant in the disc space
with a pushing force applied by manipulating the handle manually or
with a mallet or other instrument. The hook instruments can
re-position the implants by pivoting and pulling either manually or
with supplemental instruments, such as with the tuning instrument.
The extractor instruments can be employed to re-position the
implants, or to remove the implants for another insertion attempt.
The instruments can also be employed in revision procedures where a
second surgical procedure is performed to access and re-position or
remove the implant.
The re-positioning and extraction instruments can be provided in a
kit, either separately or along with instruments for positioning
the implants in the space between vertebrae. The kit can include a
spinal implant with a wall defining a size and shape for
positioning between vertebrae and at least one receptacle in the
wall. The kit can also include a rotator instrument including a
shaft extending along a longitudinal axis between a proximal handle
and a distal end member that has a distal end wall with a shape to
conform to a portion of the wall of the implant. The kit can also
include a hook instrument that includes a shaft extending along a
longitudinal axis between a proximal handle and a distal hook
member configured to engage the implant in the at least one
receptacle. The kit can further include an extractor instrument
including a shaft assembly operably linking a proximal actuator
assembly and a distal engaging assembly that is operable with the
actuator assembly to clampingly engage the implant.
In one embodiment, the kit can also include a second hook
instrument with a shaft extending along a longitudinal axis between
a proximal handle and a distal hook member that is configured to
engage the implant in the at least one receptacle. One of the hook
members in the kit includes a linear arm extending from the shaft
to a distal hooked end and the other of the hook members includes
an angled arm extending from the shaft to a distal hooked end.
In another embodiment, the engaging assembly of the extractor
instrument in the kit includes a clamping member movable with the
actuator assembly and a support member fixed to the shaft assembly.
In one form, the clamping member is movable longitudinally with the
actuator assembly to clampingly engage said implant between said
clamping member and said support member. In another form, the
clamping member is pivotally movable with the actuator assembly to
clampingly engage the implant between the clamping member and the
support member.
In a further embodiment, the distal end wall of the rotator
instrument in the kit includes a concave curvature extending
transversely to the longitudinal axis.
In yet another embodiment, the kit can include a tuning instrument
having a forked end. The hook instrument includes an adjustment
member extending outwardly from the shaft, and the forked end is
sized for positioning about the shaft of the hook instrument in
contact with the adjustment member.
While the invention has been illustrated and described in detail in
the drawings and the foregoing description, the same is considered
to be illustrative and not restrictive in character. All changes
and modifications that come within the spirit of the invention are
desired to be protected.
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